Bones and bony structures are susceptible to a variety of weaknesses that can affect their ability to provide support and structure. Weaknesses in bony structures have numerous potential causes, including degenerative diseases, tumors, fractures, and dislocations. Advances in medicine and engineering have provided doctors with a plurality of devices and techniques for alleviating or curing these weaknesses.    In some cases, the spinal column requires additional support in order to address such weaknesses. One technique for providing support is to extend a structure between adjacent bones, the structure connected at each end to a polyaxial screw “tulip”, or yoke, the yoke connected to a bone screw inserted within the bone, the structure, yoke, and bone screw all rigidly mutually secured by a locking cap applied to the yoke.